diff --git a/luprex/core/cpp/animqueue.cpp b/luprex/core/cpp/animqueue.cpp
index e5dd764d..5e4b7c2a 100644
--- a/luprex/core/cpp/animqueue.cpp
+++ b/luprex/core/cpp/animqueue.cpp
@@ -1,6 +1,6 @@
 #include "wrap-sstream.hpp"
 #include "wrap-map.hpp"
-
+#include "util.hpp"
 #include "animqueue.hpp"
 #include "luastack.hpp"
 #include "streambuffer.hpp"
@@ -297,25 +297,25 @@ bool AnimStep::from_string(const eng::string &config) {
         if (key == "action") {
             action_ = val;
         } else if (key == "id") {
-            int64_t id = util::str_to_int64(val, -1);
+            int64_t id = sv::to_int64(val, -1);
             if (id < 0) return false;
             id_ = id;
         } else if (key == "plane") {
             set_plane(val);
         } else if (key == "x") {
-            double v = util::str_to_double(val);
+            double v = sv::to_double(val);
             if (std::isnan(v)) return false;
             set_x(v);
         } else if (key == "y") {
-            double v = util::str_to_double(val);
+            double v = sv::to_double(val);
             if (std::isnan(v)) return false;
             set_y(v);
         } else if (key == "z") {
-            double v = util::str_to_double(val);
+            double v = sv::to_double(val);
             if (std::isnan(v)) return false;
             set_z(v);
         } else if (key == "facing") {
-            double v = util::str_to_double(val);
+            double v = sv::to_double(val);
             if (std::isnan(v)) return false;
             set_facing(v);
         } else if (key == "graphic") {
diff --git a/luprex/core/cpp/drivenengine.cpp b/luprex/core/cpp/drivenengine.cpp
index a3be997d..b7ce9569 100644
--- a/luprex/core/cpp/drivenengine.cpp
+++ b/luprex/core/cpp/drivenengine.cpp
@@ -1,12 +1,12 @@
 #include "wrap-string.hpp"
 #include "wrap-vector.hpp"
+#include "util.hpp"
+#include "drivenengine.hpp"
 
 #include <utility>
 #include <iostream>
 #include <cstring>
 
-#include "drivenengine.hpp"
-
 DrivenEngineReg *DrivenEngineReg::All;
 
 DrivenEngineReg::DrivenEngineReg(const char *n, DrivenEngineMaker fn) {
@@ -66,7 +66,7 @@ void Channel::echo_command() {
     }
 
     // Find out how much of the command matches.
-    int match = util::common_prefix_length(current_command_, desired_command_);
+    int match = sv::common_prefix_length(current_command_, desired_command_);
 
     // Echo backspaces to remove the non-matching part.
     int remove = current_command_.size() - match;
diff --git a/luprex/core/cpp/driver-util.cpp b/luprex/core/cpp/driver-util.cpp
index ba905f27..1997544b 100644
--- a/luprex/core/cpp/driver-util.cpp
+++ b/luprex/core/cpp/driver-util.cpp
@@ -1,17 +1,16 @@
 
 #include "wrap-string.hpp"
 #include "wrap-vector.hpp"
+#include "util.hpp"
+#include "spookyv2.hpp"
+#include "driver-util.hpp"
+#include "luastack.hpp"
 
 #include <string_view>
 #include <fstream>
 #include <ios>
 #include <iostream>
 
-#include "spookyv2.hpp"
-#include "driver-util.hpp"
-#include "luastack.hpp"
-#include "util.hpp"
-
 #define RLOG_BUFSIZE (1024 * 1024)
 #define MAX_ARGC 1024
 
@@ -47,8 +46,8 @@ void split_target(std::string_view target, std::string &cert, std::string &host,
 std::vector<std::string> parse_control_lst(std::string_view ctrl) {
     std::vector<std::string> result;
     while (!ctrl.empty()) {
-        std::string_view line = util::sv_read_line(ctrl);
-        std::string_view trimmed = util::sv_trim(line);
+        std::string_view line = sv::read_to_line(ctrl);
+        std::string_view trimmed = sv::trim(line);
         if ((trimmed.size() > 0) && (trimmed[0] != '#')) {
             result.emplace_back(trimmed);
         }
diff --git a/luprex/core/cpp/gui.cpp b/luprex/core/cpp/gui.cpp
index fc8f77dc..91b53e66 100644
--- a/luprex/core/cpp/gui.cpp
+++ b/luprex/core/cpp/gui.cpp
@@ -1,7 +1,7 @@
 #include "wrap-string.hpp"
 #include "wrap-map.hpp"
 #include "wrap-vector.hpp"
-
+#include "util.hpp"
 #include "gui.hpp"
 #include "luastack.hpp"
 
@@ -62,7 +62,7 @@ LuaDefine(gui_menu_item, "action,label", "add a menu item to the current gui") {
     LuaStack LS(L, laction, llabel);
     eng::string action = LS.ckstring(laction);
     eng::string label = LS.ckstring(llabel);
-    if (!util::has_prefix(action, "cb_")) {
+    if (!sv::has_prefix(action, "cb_")) {
         luaL_error(L, "menuitem callbacks must start with cb_");
     }
     gui->menu_item(action, label);
diff --git a/luprex/core/cpp/http.cpp b/luprex/core/cpp/http.cpp
index 8f941524..11850670 100644
--- a/luprex/core/cpp/http.cpp
+++ b/luprex/core/cpp/http.cpp
@@ -2,7 +2,9 @@
 #include "http.hpp"
 #include "wrap-sstream.hpp"
 #include "wrap-string.hpp"
+#include "util.hpp"
 #include "luastack.hpp"
+
 #include <cstdint>
 
 static void url_encode(const eng::string &value, StreamBuffer *sb) {
@@ -10,7 +12,7 @@ static void url_encode(const eng::string &value, StreamBuffer *sb) {
     for (int i = 0; i < int(value.size()); i++) {
         char c = value[i];
 
-        if (util::ascii_isalnum(c) || c == '-' || c == '_' || c == '.' || c == '~' || (c == '/')) {
+        if (sv::ascii_isalnum(c) || c == '-' || c == '_' || c == '.' || c == '~' || (c == '/')) {
             sb->write_char(c);
         } else if (c == ' ') {
             sb->write_char('+');
@@ -77,7 +79,7 @@ void HttpRequest::set_host(const eng::string &s) {
     // This is not quite strict, but it's close.  I believe
     // the DNS lookup will fail for invalid hostnames anyway.
     for (char c : host) {
-        if ((c != '-') && (c != '.') && (!util::ascii_isalnum(c))) {
+        if ((c != '-') && (c != '.') && (!sv::ascii_isalnum(c))) {
             ErrorStringStream error(&error_);
             error << "HTTPS hostnames can only contain letters, digits, and hyphen: " << host;
             return;
@@ -106,11 +108,11 @@ void HttpRequest::set_port(int port) {
 }
 
 void HttpRequest::set_url(const eng::string &url) {
-    if (util::has_prefix(url, "https://")) {
+    if (sv::has_prefix(url, "https://")) {
         ErrorStringStream error(&error_);
         error << "set_url(full_url) not implemented yet.";
         return;
-    } else if (util::has_prefix(url, "/")) {
+    } else if (sv::has_prefix(url, "/")) {
         if (!path_.empty()) {
             ErrorStringStream error(&error_);
             error << "HTTP path specified twice: " << path_ << " and " << url;
@@ -338,11 +340,6 @@ void HttpResponse::fail(int response_code, const eng::string &error) {
     content_ = "";
 }
 
-static std::string_view readline(std::string_view &v) {
-    std::string_view result = util::sv_split_one(v, '\n');
-    return util::sv_rtrim(result, '\r');    
-}
-
 void HttpResponse::parse(const StreamBuffer *sb) {
     // We're not going to modify the StreamBuffer at all.
     // Instead, we work entirely on a view.
@@ -355,7 +352,7 @@ void HttpResponse::parse(const StreamBuffer *sb) {
     }
 
     // Parse the status line.
-    std::string_view status = readline(view);
+    std::string_view status = sv::read_to_line(view);
     if (status.empty()) {
         fail(500, "HTTP status-line not present in response");
         return;
diff --git a/luprex/core/cpp/lpxclient.cpp b/luprex/core/cpp/lpxclient.cpp
index c2c39832..8e113806 100644
--- a/luprex/core/cpp/lpxclient.cpp
+++ b/luprex/core/cpp/lpxclient.cpp
@@ -125,13 +125,13 @@ public:
 
     void do_menu_command(const StringVec &cmd) {
         world_to_asynchronous();
-        int64_t place = util::str_to_int64(cmd[1], actor_id_);
+        int64_t place = sv::to_int64(cmd[1], actor_id_);
         world_->update_gui(actor_id_, place, &gui_);
         stdostream() << gui_.menu_debug_string();
     }
 
     void do_choose_command(const StringVec &cmd) {
-        eng::string action = gui_.get_action(util::str_to_int64(cmd[1]));
+        eng::string action = gui_.get_action(sv::to_int64(cmd[1]));
         if (action == "") {
             stdostream() << "Invalid menu item #" << std::endl;
             return;
diff --git a/luprex/core/cpp/luaconsole.cpp b/luprex/core/cpp/luaconsole.cpp
index bfb21d8c..5f6204bc 100644
--- a/luprex/core/cpp/luaconsole.cpp
+++ b/luprex/core/cpp/luaconsole.cpp
@@ -1,8 +1,7 @@
-#include "eng-malloc.hpp"
-#include "luastack.hpp"
 #include "wrap-string.hpp"
 #include "wrap-vector.hpp"
-
+#include "eng-malloc.hpp"
+#include "luastack.hpp"
 #include "luaconsole.hpp"
 #include "util.hpp"
 
@@ -53,7 +52,7 @@ void LuaConsole::simplify(const StringVec &words) {
     words_ = words;
     if (words.size() == 0) {
         return;
-    } else if (util::valid_int64(words[0])) {
+    } else if (sv::valid_int64(words[0])) {
         if (words.size() == 1) {
             words_.clear();
             words_.push_back("choose");
@@ -62,7 +61,7 @@ void LuaConsole::simplify(const StringVec &words) {
             synerr("/choose command takes no arguments");
         }
     } else if (words[0] == "choose") {
-        if ((words.size() == 2)&&(util::valid_int64(words[1]))) {
+        if ((words.size() == 2)&&(sv::valid_int64(words[1]))) {
             // OK
         } else {
             synerr("/choose [menu-line-number]");
@@ -74,7 +73,7 @@ void LuaConsole::simplify(const StringVec &words) {
     } else if (words[0] == "menu") {
         if (words.size() == 1) {
             words_.push_back("-");
-        } else if ((words.size() == 2)&&(util::valid_int64(words[1]))) {
+        } else if ((words.size() == 2)&&(sv::valid_int64(words[1]))) {
             // OK
         } else {
             synerr("/menu [optional-tangible-id]");
@@ -126,13 +125,13 @@ void LuaConsole::add(eng::string line) {
     // Translate lua expression, deal with initial prefix.
     eng::string partial;
     eng::string lua_mode;
-    if (util::has_prefix(raw_input_, "?=")) {
+    if (sv::has_prefix(raw_input_, "?=")) {
         lua_mode = "luaprobe";
         partial = eng::string("return ") + raw_input_.substr(2);
-    } else if (util::has_prefix(raw_input_, "?")) {
+    } else if (sv::has_prefix(raw_input_, "?")) {
         lua_mode = "luaprobe";
         partial = raw_input_.substr(1);
-    } else if (util::has_prefix(raw_input_, "=")) {
+    } else if (sv::has_prefix(raw_input_, "=")) {
         lua_mode = "luainvoke";
         partial = eng::string("return ") + raw_input_.substr(1);
     } else {
@@ -157,7 +156,7 @@ void LuaConsole::add(eng::string line) {
         }
     } else {
         words_.push_back(lua_mode);
-        words_.push_back(util::rtrim(partial));
+        words_.emplace_back(sv::rtrim(partial));
         clear_raw_input();
     }
     lua_settop(lua_state_, top);
diff --git a/luprex/core/cpp/pprint.cpp b/luprex/core/cpp/pprint.cpp
index 8185a11f..2b4d22f4 100644
--- a/luprex/core/cpp/pprint.cpp
+++ b/luprex/core/cpp/pprint.cpp
@@ -197,7 +197,7 @@ static void pprint_r(Inspector &insp, int level, LuaSlot root) {
         } else {
             multiline = true;
             tabify(insp, level + 1);
-            if (LS.isstring(key) && util::is_identifier(LS.ckstring(key))) {
+            if (LS.isstring(key) && sv::is_lua_id(LS.ckstring(key))) {
                 (*insp.stream) << LS.ckstring(key);
             } else {
                 (*insp.stream) << "[";
@@ -254,7 +254,7 @@ LuaDefine(string_isidentifier, "str", "return true if the string is a valid lua
     LuaStack LS(L, str, result);
     if (LS.isstring(str)) {
         eng::string s = LS.ckstring(str);
-        LS.set(result, util::is_identifier(s));
+        LS.set(result, sv::is_lua_id(s));
     } else {
         LS.set(result, false);
     }
diff --git a/luprex/core/cpp/source.cpp b/luprex/core/cpp/source.cpp
index 1a7f32e2..fede292a 100644
--- a/luprex/core/cpp/source.cpp
+++ b/luprex/core/cpp/source.cpp
@@ -7,7 +7,6 @@
 #include "wrap-map.hpp"
 #include "wrap-set.hpp"
 #include "wrap-sstream.hpp"
-
 #include "util.hpp"
 #include "luastack.hpp"
 #include "traceback.hpp"
@@ -569,7 +568,7 @@ eng::string SourceDB::function_docs(const LuaStack &LS0, LuaSlot fn) {
 
         // Incorporate the function comment.
         int linelo = linehi;
-        while ((linelo > 0) && (util::is_lua_comment(lines[linelo-1]))) linelo -= 1;
+        while ((linelo > 0) && (sv::is_lua_comment(lines[linelo-1]))) linelo -= 1;
         
         // Output the docs.
         eng::ostringstream result;
diff --git a/luprex/core/cpp/textgame.cpp b/luprex/core/cpp/textgame.cpp
index 29a94784..cfac55c2 100644
--- a/luprex/core/cpp/textgame.cpp
+++ b/luprex/core/cpp/textgame.cpp
@@ -1,7 +1,6 @@
 
 #include "wrap-vector.hpp"
 #include "wrap-string.hpp"
-
 #include "luastack.hpp"
 #include "util.hpp"
 #include "gui.hpp"
@@ -47,13 +46,13 @@ private:
     }
 
     void do_menu_command(const StringVec &cmd) {
-        int64_t place = util::str_to_int64(cmd[1], actor_id_);
+        int64_t place = sv::to_int64(cmd[1], actor_id_);
         world_->update_gui(actor_id_, place, &gui_);
         stdostream() << gui_.menu_debug_string();
     }
 
     void do_choose_command(const StringVec &cmd) {
-        eng::string action = gui_.get_action(util::str_to_int64(cmd[1]));
+        eng::string action = gui_.get_action(sv::to_int64(cmd[1]));
         if (action == "") {
             stdostream() << "Invalid menu item #" << std::endl;
             return;
diff --git a/luprex/core/cpp/util.cpp b/luprex/core/cpp/util.cpp
index 659cab92..47343748 100644
--- a/luprex/core/cpp/util.cpp
+++ b/luprex/core/cpp/util.cpp
@@ -1,11 +1,10 @@
 #include "wrap-string.hpp"
 #include "wrap-vector.hpp"
+#include "util.hpp"
 #include "fast-float.hpp"
 
+
 #include <algorithm>
-
-#include "util.hpp"
-
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <iomanip>
@@ -23,29 +22,113 @@
 #include <unistd.h>
 #endif
 
-namespace util {
+namespace sv {
 
-eng::string ascii_tolower(const eng::string &s) {
-    eng::string mod = s;
-    for (int i = 0; i < int(mod.size()); i++) {
-        if (ascii_isupper(mod[i])) {
-            mod[i] += 'a' - 'A';
-        }
-    }
-    return mod;
+bool valid_int64(string_view value) {
+    int64_t result;
+    const char *last = value.data() + value.size();
+    auto r = std::from_chars(value.data(), last, result, 10);
+    if (r.ec != std::errc()) return false;
+    if (r.ptr != last) return false;
+    return true;
 }
 
-eng::string ascii_toupper(const eng::string &s) {
-    eng::string mod = s;
-    for (int i = 0; i < int(mod.size()); i++) {
-        if (ascii_islower(mod[i])) {
-            mod[i] += 'A' - 'a';
-        }
-    }
-    return mod;
+bool valid_double(string_view value) {
+    double result;
+    const char *last = value.data() + value.size();
+    auto r = fast_float::from_chars(value.data(), last, result);
+    if (r.ec != std::errc()) return false;
+    if (r.ptr != last) return false;
+    return true;
 }
 
-bool is_identifier(const eng::string &str) {
+int64_t to_int64(string_view value, int64_t errval) {
+    int64_t result;
+    const char *last = value.data() + value.size();
+    auto r = std::from_chars(value.data(), last, result, 10);
+    if (r.ec != std::errc()) return errval;
+    if (r.ptr != last) return errval;
+    return result;
+}
+
+double to_double(string_view value, double errval) {
+    double result;
+    const char *last = value.data() + value.size();
+    auto r = fast_float::from_chars(value.data(), last, result);
+    if (r.ec != std::errc()) return errval;
+    if (r.ptr != last) return errval;
+    return result;
+}
+
+string_view ltrim(string_view v) {
+    while ((!v.empty()) && (ascii_isspace(v.front()))) {
+        v.remove_prefix(1);
+    }
+    return v;
+}
+
+string_view rtrim(string_view v) {
+    while ((!v.empty()) && (ascii_isspace(v.back()))) {
+        v.remove_suffix(1);
+    }
+    return v;
+}
+
+string_view trim(string_view v) {
+    while ((!v.empty()) && (ascii_isspace(v.front()))) {
+        v.remove_prefix(1);
+    }
+    while ((!v.empty()) && (ascii_isspace(v.back()))) {
+        v.remove_suffix(1);
+    }
+    return v;
+}
+
+string_view ltrim(string_view v, char c) {
+    while ((!v.empty()) && (v.front() == c)) {
+        v.remove_prefix(1);
+    }
+    return v;
+}
+
+string_view rtrim(string_view v, char c) {
+    while ((!v.empty()) && (v.back() == c)) {
+        v.remove_suffix(1);
+    }
+    return v;
+}
+
+string_view trim(string_view v, char c) {
+    while ((!v.empty()) && (v.front() == c)) {
+        v.remove_prefix(1);
+    }
+    while ((!v.empty()) && (v.back() == c)) {
+        v.remove_suffix(1);
+    }
+    return v;
+}
+
+bool has_prefix(string_view s, string_view prefix) {
+    return 0 == s.compare(0, prefix.size(), prefix);
+}
+
+bool has_suffix(string_view s, string_view suffix) {
+    if (s.length() >= suffix.length()) {
+        return (0 == s.compare (s.length() - suffix.length(), suffix.length(), suffix));
+    } else {
+        return false;
+    }
+}
+
+int common_prefix_length(string_view a, string_view b) {
+    int minlen = std::min(a.size(), b.size());
+    for (int i = 0; i < minlen; i++) {
+        if (a[i] != b[i]) return i;
+    }
+    return minlen;
+}
+
+bool is_lua_id(string_view str) {
     if (str.size() == 0) return false;
     char c=str[0];
     if ((!ascii_isalpha(c)) && (c!='_')) return false;
@@ -56,6 +139,84 @@ bool is_identifier(const eng::string &str) {
     return true;
 }
 
+bool is_lua_comment(string_view s) {
+    int start = 0;
+    while ((start < int(s.size())) && ((s[start]==' ') || (s[start]=='\t'))) start++;
+    return s.substr(start, 2) == "--";
+}
+
+string_view read_to_sep(string_view &source, char sep) {
+    size_t pos = source.find(sep);
+    string_view result;
+    if (pos == string_view::npos) {
+        result = source;
+        source = string_view();
+    } else {
+        result = source.substr(0, pos);
+        source = source.substr(pos + 1);
+    }
+    return result;
+}
+
+string_view read_to_line(string_view &source) {
+    size_t pos = source.find('\n');
+    string_view result;
+    if (pos == string_view::npos) {
+        result = source;
+        source = string_view();
+    } else {
+        result = source.substr(0, pos);
+        source = source.substr(pos + 1);
+    }
+    if ((!result.empty()) && (result.back() == '\r')) {
+        result.remove_suffix(1);
+    }
+    return result;
+}
+
+string_view read_to_space(string_view &source) {
+    size_t pos1 = 0;
+    while ((pos1 < source.size()) && (!ascii_isspace(source[pos1]))) {
+        pos1 += 1;
+    }
+    string_view result = source.substr(0, pos1);
+    if (pos1 == source.size()) {
+        source = string_view();
+        return result;
+    }
+    size_t pos2 = pos1 + 1;
+    while ((pos2 < source.size()) && (ascii_isspace(source[pos2]))) {
+        pos2 += 1;
+    }
+    source = source.substr(pos2);
+    return result;
+}
+
+} // namespace sv
+
+
+namespace util {
+
+eng::string ascii_tolower(std::string_view s) {
+    eng::string mod(s);
+    for (int i = 0; i < int(mod.size()); i++) {
+        if (sv::ascii_isupper(mod[i])) {
+            mod[i] += 'a' - 'A';
+        }
+    }
+    return mod;
+}
+
+eng::string ascii_toupper(std::string_view s) {
+    eng::string mod(s);
+    for (int i = 0; i < int(mod.size()); i++) {
+        if (sv::ascii_islower(mod[i])) {
+            mod[i] += 'A' - 'a';
+        }
+    }
+    return mod;
+}
+
 void quote_string(const eng::string &s, std::ostream *os) {
     bool anysq = false;
     bool anydq = false;
@@ -251,14 +412,6 @@ eng::string repeat_string(const eng::string &a, int n) {
     }
     return result;
 }
-
-int common_prefix_length(const eng::string &a, const eng::string &b) {
-    int minlen = std::min(a.size(), b.size());
-    for (int i = 0; i < minlen; i++) {
-        if (a[i] != b[i]) return i;
-    }
-    return minlen;
-}
     
 eng::string tolower(eng::string input) {
     for (int i = 0; i < int(input.size()); i++) {
@@ -274,148 +427,6 @@ eng::string toupper(eng::string input) {
     return input;
 }
 
-bool has_prefix(const eng::string &s, const eng::string &prefix) {
-    return 0 == s.compare(0, prefix.size(), prefix);
-}
-
-bool has_suffix(const eng::string &s, const eng::string &suffix) {
-    if (s.length() >= suffix.length()) {
-        return (0 == s.compare (s.length() - suffix.length(), suffix.length(), suffix));
-    } else {
-        return false;
-    }
-}
-
-bool valid_int64(std::string_view value) {
-    int64_t result;
-    const char *last = value.data() + value.size();
-    auto r = std::from_chars(value.data(), last, result, 10);
-    if (r.ec != std::errc()) return false;
-    if (r.ptr != last) return false;
-    return true;
-}
-
-int64_t str_to_int64(std::string_view value, int64_t errval) {
-    int64_t result;
-    const char *last = value.data() + value.size();
-    auto r = std::from_chars(value.data(), last, result, 10);
-    if (r.ec != std::errc()) return errval;
-    if (r.ptr != last) return errval;
-    return result;
-}
-
-bool valid_double(std::string_view value) {
-    double result;
-    const char *last = value.data() + value.size();
-    auto r = fast_float::from_chars(value.data(), last, result);
-    if (r.ec != std::errc()) return false;
-    if (r.ptr != last) return false;
-    return true;
-}
-
-double str_to_double(std::string_view value, double errval) {
-    double result;
-    const char *last = value.data() + value.size();
-    auto r = fast_float::from_chars(value.data(), last, result);
-    if (r.ec != std::errc()) return errval;
-    if (r.ptr != last) return errval;
-    return result;
-}
-
-std::string_view sv_ltrim(std::string_view v) {
-    const char *b = v.data();
-    const char *e = v.data() + v.size();
-    while ((e > b) && (std::isspace(b[0]))) {
-        b++;
-    }
-    return std::string_view(b, e-b);
-}
-
-std::string_view sv_rtrim(std::string_view v) {
-    const char *b = v.data();
-    const char *e = v.data() + v.size();
-    while ((e > b) && (std::isspace(e[-1]))) {
-        e--;
-    }
-    return std::string_view(b, e-b);
-}
-
-std::string_view sv_trim(std::string_view v) {
-    const char *b = v.data();
-    const char *e = v.data() + v.size();
-    while ((e > b) && (std::isspace(b[0]))) {
-        b++;
-    }
-    while ((e > b) && (std::isspace(e[-1]))) {
-        e--;
-    }
-    return std::string_view(b, e-b);
-}
-
-std::string_view sv_ltrim(std::string_view v, char c) {
-    while ((!v.empty()) && (v.front() == c)) {
-        v.remove_prefix(1);
-    }
-    return v;
-}
-
-std::string_view sv_rtrim(std::string_view v, char c) {
-    while ((!v.empty()) && (v.back() == c)) {
-        v.remove_suffix(1);
-    }
-    return v;
-}
-
-std::string_view sv_trim(std::string_view v, char c) {
-    while ((!v.empty()) && (v.front() == c)) {
-        v.remove_prefix(1);
-    }
-    while ((!v.empty()) && (v.back() == c)) {
-        v.remove_suffix(1);
-    }
-    return v;
-}
-
-eng::string ltrim(std::string_view v) {
-    return eng::string(sv_ltrim(v));
-}
-
-eng::string rtrim(std::string_view v) {
-    return eng::string(sv_rtrim(v));
-}
-
-eng::string trim(std::string_view v) {
-    return eng::string(sv_trim(v));
-}
-
-std::string_view sv_split_one(std::string_view &v, char sep) {
-    size_t pos = v.find(sep);
-
-    // If there's no separator in the buffer, return a null view.
-    if (pos == std::string_view::npos) {
-        return std::string_view();
-    }
-
-    // Split into stuff before the separator, and stuff after.
-    std::string_view result = v.substr(0, pos);
-    v = v.substr(pos + 1);
-    return result;
-}
-
-std::string_view sv_read_line(std::string_view &source) {
-    size_t pos = source.find('\n');
-    std::string_view result;
-    if (pos == std::string_view::npos) {
-        result = source;
-        source = std::string_view();
-    } else {
-        result = source.substr(0, pos);
-        source = source.substr(pos + 1);
-    }
-    result = sv_rtrim(result, '\r');
-    return result;
-}
-
 double distance_squared(double x1, double y1, double x2, double y2) {
     double dx = x1 - x2;
     double dy = y1 - y2;
@@ -433,12 +444,6 @@ LuaSourcePtr make_lua_source(const eng::string &code) {
     return result;
 }
 
-bool is_lua_comment(const eng::string &s) {
-    int start = 0;
-    while ((start < int(s.size())) && ((s[start]==' ') || (s[start]=='\t'))) start++;
-    return s.substr(start, 2) == "--";
-}
-
 eng::string XYZ::debug_string() const {
     eng::ostringstream oss;
     oss << "(" << x << "," << y << "," << z << ")";
@@ -468,6 +473,57 @@ std::ostream &operator<<(std::ostream &oss, const util::hex8 &v) {
 }
 
 LuaDefine(unittests_util, "", "some unit tests") {
+        // test str_to_int64, str_to_double
+    LuaAssert(L, sv::to_int64("123") == 123);
+    LuaAssert(L, sv::to_int64("123.4") == INT64_MIN);
+    LuaAssert(L, sv::to_int64("12ab") == INT64_MIN);
+    LuaAssert(L, sv::to_int64("") == INT64_MIN);
+    LuaAssert(L, sv::to_double("123.5") == 123.5);
+    LuaAssert(L, std::isnan(sv::to_double("12ab")));
+    LuaAssert(L, std::isnan(sv::to_double("")));
+    
+    // Test trim, ltrim, rtrim
+    LuaAssert(L, sv::ltrim("  foo  ") == "foo  ");
+    LuaAssert(L, sv::rtrim("  foo  ") == "  foo");
+    LuaAssert(L, sv::trim("  foo  ") == "foo");
+    LuaAssert(L, sv::trim("foo") == "foo");
+    LuaAssert(L, sv::trim("") == "");
+    LuaAssert(L, sv::ltrim("**foo**", '*') == "foo**");
+    LuaAssert(L, sv::rtrim("**foo**", '*') == "**foo");
+    LuaAssert(L, sv::trim("**foo**", '*') == "foo");
+    LuaAssert(L, sv::trim("foo", '*') == "foo");
+    LuaAssert(L, sv::trim("", '*') == "");
+    
+    // Test read_to_line
+    std::string_view v = "foo\nbar\r\nbaz";
+    
+    std::string_view v1 = sv::read_to_line(v);
+    LuaAssertStrEq(L, v1, "foo");
+    LuaAssertStrEq(L, v, "bar\r\nbaz");
+
+    std::string_view v2 = sv::read_to_line(v);
+    LuaAssertStrEq(L, v2, "bar");
+    LuaAssertStrEq(L, v, "baz");
+
+    std::string_view v3 = sv::read_to_line(v);
+    LuaAssertStrEq(L, v3, "baz");
+    LuaAssert(L, sv::isnull(v));
+
+    // Test read_to_space
+    v = "foo  bar  baz";
+
+    std::string_view s1 = sv::read_to_space(v);
+    LuaAssertStrEq(L, s1, "foo");
+    LuaAssertStrEq(L, v, "bar  baz");
+
+    std::string_view s2 = sv::read_to_space(v);
+    LuaAssertStrEq(L, s2, "bar");
+    LuaAssertStrEq(L, v, "baz");
+
+    std::string_view s3 = sv::read_to_space(v);
+    LuaAssertStrEq(L, s3, "baz");
+    LuaAssert(L, sv::isnull(v));
+
     // Test the unioning of ID vectors.
     util::IdVector idv1,idv2;
     idv1.push_back(1);
@@ -512,31 +568,6 @@ LuaDefine(unittests_util, "", "some unit tests") {
     LuaAssert(L, util::toupper("fooBar") == "FOOBAR");
     LuaAssert(L, util::tolower("fooBar") == "foobar");
 
-    // test str_to_int64, str_to_double
-    LuaAssert(L, util::str_to_int64("123") == 123);
-    LuaAssert(L, util::str_to_int64("123.4") == INT64_MIN);
-    LuaAssert(L, util::str_to_int64("12ab") == INT64_MIN);
-    LuaAssert(L, util::str_to_int64("") == INT64_MIN);
-    LuaAssert(L, util::str_to_double("123.5") == 123.5);
-    LuaAssert(L, std::isnan(util::str_to_double("12ab")));
-    LuaAssert(L, std::isnan(util::str_to_double("")));
-    
-    // Test trim, ltrim, rtrim
-    LuaAssert(L, util::ltrim("  foo  ") == "foo  ");
-    LuaAssert(L, util::rtrim("  foo  ") == "  foo");
-    LuaAssert(L, util::trim("  foo  ") == "foo");
-    LuaAssert(L, util::trim("foo") == "foo");
-    LuaAssert(L, util::trim("") == "");
-    
-    // Test sv_read_line
-    std::string_view v = "foo\nbar\r\n";
-    std::string_view v1 = util::sv_read_line(v);
-    std::string_view v2 = util::sv_read_line(v);
-    std::string_view v3 = util::sv_read_line(v);
-    LuaAssertStrEq(L, v1, "foo");
-    LuaAssertStrEq(L, v2, "bar");
-    LuaAssertStrEq(L, v3, "");
-
     // Test distance_squared
     LuaAssert(L, util::distance_squared(1, 1, 5, 4) == 25.0);
     LuaAssert(L, util::distance_squared(5, 4, 1, 1) == 25.0);
diff --git a/luprex/core/cpp/util.hpp b/luprex/core/cpp/util.hpp
index e30734d0..0ea0b96a 100644
--- a/luprex/core/cpp/util.hpp
+++ b/luprex/core/cpp/util.hpp
@@ -1,3 +1,18 @@
+///////////////////////////////////////////////////////////////////////
+//
+// NAMESPACE SV
+//
+//  * Operate on string_view or just characters.
+//  * Do not allocate memory.
+//  * Do not copy strings.
+//
+// NAMESPACE UTIL
+//
+//  * General purpose utility functions.
+//  * Sort of a catch-all.
+//
+///////////////////////////////////////////////////////////////////////
+
 #ifndef UTIL_HPP
 #define UTIL_HPP
 
@@ -15,6 +30,92 @@
 #include "luastack.hpp"
 #include "spookyv2.hpp"
 
+namespace sv {
+
+// Bring this into our namespace.
+using string_view = std::string_view;
+
+// Test character class, ignoring current locale and unicode issues.
+inline bool ascii_isupper(char c) { return (c >= 'A') && (c <= 'Z'); }
+inline bool ascii_islower(char c) { return (c >= 'a') && (c <= 'z'); }
+inline bool ascii_isdigit(char c) { return (c >= '0') && (c <= '9'); }
+inline bool ascii_isalpha(char c) { return ascii_isupper(c) || ascii_islower(c); }
+inline bool ascii_isalnum(char c) { return ascii_isalpha(c) || ascii_isdigit(c); }
+inline bool ascii_isspace(char c) { return (c==' ')||(c=='\t')||(c=='\r')||(c=='\n')||(c=='\f')||(c=='\v'); }
+
+// Check for the null string_view
+//
+// Note that the null string view is an empty string, 
+// but not every empty string is the null string view.
+//
+inline bool isnull(string_view v) { return v.data() == nullptr; }
+
+// Check if numbers can be parsed as int64/double
+bool valid_int64(string_view v);
+bool valid_double(string_view v);
+
+// Parse numbers as int64/double.  Returns errval on failure.
+int64_t to_int64(string_view v, int64_t errval = std::numeric_limits<int64_t>::min());
+double to_double(string_view v, double errval = std::numeric_limits<double>::quiet_NaN());
+
+// Trim whitspace from a string_view.
+string_view ltrim(string_view v);
+string_view rtrim(string_view v);
+string_view trim(string_view v);
+
+// Trim specific character (all occurrences) from a string_view.
+string_view ltrim(string_view v, char c);
+string_view rtrim(string_view v, char c);
+string_view trim(string_view v, char c);
+
+// Return true if the string has the specified prefix or suffix.
+bool has_prefix(string_view s, string_view prefix);
+bool has_suffix(string_view s, string_view suffix);
+
+// Return the length of the common prefix of A and B.
+int common_prefix_length(string_view a, string_view b);
+
+// Return true if the string is a lua identifier.
+bool is_lua_id(string_view s);
+
+// Return true if the line of code is a lua comment.
+bool is_lua_comment(string_view s);
+
+// Read from a string_view until separator is reached.
+//
+// If the separator appears in the source, returns everything
+// before the separator, and updates the source to everything
+// after the separator.
+//
+// If the separator doesn't appear in the source, returns
+// the entire source, and replaces source with the null string_view.
+//
+string_view read_to_sep(string_view &source, char sep);
+
+// Read from a string_view until newline is reached.
+//
+// If there's a line-break in the source (newline or CRLF),
+// returns the text before the line-break, and updates the
+// source to the text after the line-break.
+//
+// If there's no line-break in the source, returns the entire source,
+// and updates source to the null string_view.
+//
+string_view read_to_line(string_view &source);
+
+// Read from a string_view until whitespace is reached.
+//
+// If there's any whitespace in the source, returns the text
+// before the whitespace, and update the source to the text
+// after the whitespace.
+//
+// If there's no whitespace in the source, returns the entire
+// source, and updates the source to the null string_view.
+//
+string_view read_to_space(string_view &source);
+
+} // namespace sv
+
 namespace util {
 
 enum WorldType {
@@ -38,26 +139,14 @@ using LuaSourceVec = eng::vector<StringPair>;
 using LuaSourcePtr = std::unique_ptr<LuaSourceVec>;
 using HashValue = std::pair<uint64_t, uint64_t>;
 using IdVector = eng::vector<int64_t>;
-using OptionalInt64 = std::optional<int64_t>;
 
-// This value is sometimes used to represent 'bad integer'
-const int64_t BADINT64 = std::numeric_limits<int64_t>::min();
-
-// Test character class ignoring 'current locale'.
-inline bool ascii_isupper(char c) { return (c >= 'A') && (c <= 'Z'); }
-inline bool ascii_islower(char c) { return (c >= 'a') && (c <= 'z'); }
-inline bool ascii_isdigit(char c) { return (c >= '0') && (c <= '9'); }
-inline bool ascii_isalpha(char c) { return ascii_isupper(c) || ascii_islower(c); }
-inline bool ascii_isalnum(char c) { return ascii_isalpha(c) || ascii_isdigit(c); }
-eng::string ascii_tolower(const eng::string &c);
-eng::string ascii_toupper(const eng::string &c);
+// Ascii uppercase and lowercase.
+eng::string ascii_tolower(std::string_view c);
+eng::string ascii_toupper(std::string_view c);
 
 // Return seconds elapsed, for profiling purposes.
 double profiling_clock();
 
-// Return true if the string is a valid lua identifier.
-bool is_identifier(const eng::string &str);
-
 // Output a string to a stream using Lua string escaping and quoting.
 void quote_string(const eng::string &str, std::ostream *os);
 
@@ -101,50 +190,10 @@ eng::string join(const StringVec &strs, eng::string sep);
 // Return N repetitions of string A
 eng::string repeat_string(const eng::string &a, int n);
 
-// Return the length of the common prefix of A and B.
-int common_prefix_length(const eng::string &a, const eng::string &b);
-
 // String to lowercase/uppercase.  Ascii only, no unicode.
 eng::string tolower(eng::string input);
 eng::string toupper(eng::string input);
 
-// Return true if the string has the specified prefix or suffix.
-bool has_prefix(const eng::string &s, const eng::string &prefix);
-bool has_suffix(const eng::string &s, const eng::string &suffix);
-
-// Check if numbers can be parsed as int64/double
-bool valid_int64(std::string_view v);
-bool valid_double(std::string_view v);
-
-// Parse numbers as int64/double.  Returns errval on failure.
-int64_t str_to_int64(std::string_view v, int64_t errval = INT64_MIN);
-double str_to_double(std::string_view v, double errval = std::numeric_limits<double>::quiet_NaN());
-
-// Trim a string_view
-std::string_view sv_ltrim(std::string_view v);
-std::string_view sv_rtrim(std::string_view v);
-std::string_view sv_trim(std::string_view v);
-
-std::string_view sv_ltrim(std::string_view v, char c);
-std::string_view sv_rtrim(std::string_view v, char c);
-std::string_view sv_trim(std::string_view v, char c);
-
-// sv_is_null is different from checking for empty.
-inline bool sv_is_null(const std::string_view &v) { return v.data() == nullptr; }
-
-// Split a string view into stuff before and after separator.
-// If the separator doesn't occur, returns a null string view
-// and doesn't modify the source.
-std::string_view sv_split_one(std::string_view &source, char sep);
-
-// Read a line from a string_view.
-std::string_view sv_read_line(std::string_view &source);
-
-// Trim strings: left end, right end, both ends.
-eng::string ltrim(std::string_view s);
-eng::string rtrim(std::string_view s);
-eng::string trim(std::string_view s);
-
 // Calculate distance between two points
 double distance_squared(double x1, double y1, double x2, double y2);
 
@@ -154,9 +203,6 @@ bool world_type_authoritative(util::WorldType wt);
 // Make a LuaSourceVec with one element, for unit testing.
 LuaSourcePtr make_lua_source(const eng::string &code);
 
-// Return true if the line of code is a lua comment.
-bool is_lua_comment(const eng::string &line);
-
 // Remove nullptrs from a vector of unique pointers.
 template<class T>
 void remove_nullptrs(eng::vector<std::unique_ptr<T>> &vec) {
diff --git a/luprex/core/cpp/world-core.cpp b/luprex/core/cpp/world-core.cpp
index abd6cf9a..149e25ca 100644
--- a/luprex/core/cpp/world-core.cpp
+++ b/luprex/core/cpp/world-core.cpp
@@ -5,6 +5,8 @@
 #include "gui.hpp"
 #include "traceback.hpp"
 #include "pprint.hpp"
+#include "util.hpp"
+
 #include <iostream>
 
 void World::store_global_pointer(lua_State *L, World *v) {
@@ -434,7 +436,7 @@ void World::invoke_flush_prints(int64_t actor_id, int64_t place_id, const eng::s
     if (actor_id != place_id) {
         return;
     }
-    int64_t line = util::str_to_int64(action, -1);
+    int64_t line = sv::to_int64(action, -1);
     if ((line < 0)||(line > INT_MAX)) {
         return;
     }
@@ -530,7 +532,7 @@ void World::invoke_plan(int64_t actor_id, int64_t place_id, const eng::string &a
     }
 
     // Make sure the action starts with "cb_"
-    if (!util::has_prefix(action, "cb_")) {
+    if (!sv::has_prefix(action, "cb_")) {
         return;
     }